Dumont 304 scopes
 

Hi All;
What is the difference between the Dumont 304-C and the Dumont 304-H ?? Where they like improvements -A, -B, -C etc.. Or did they stand for something such as -C, Commercial, -H, Heavy Duty, etc..
THANK YOU Marty

Scratching the head for old memories, I seem to recall that the entire series was pretty much identical. Mostly cosmetic differences, like the 401 vs the 401A, which simply had changed from inch calibrations to centimeter. I have owned several of these and don't recall any real differences. Maybe the H had higher sensitivity but I'm treading on thin ground here. Bandwidth on the entire series was about 100 kHz oops I mean 100 kc. I may still have some manuals.

Hi!
I realize this is an old thread but I wondered if I could tap your knowledge. I'm looking for a manual for a Dumont 401A. Would you still have one? Second, I saw info, online, where Fairchild took over Dumont. Would you happen to know if the Fairchild 401A is the same as the Dumont 401A?
Thanks for any info.
Bob

I think I still have Dumont 401/401A manuals. I used to own a 401R.

There were two versions, one with 'Sola' type power supply and the other with electronically regulated supply.

If anyone ever finds a manual for Dumont scope type 250-AH, I'd love to have a copy...

I believe the "H" stood for "high brightness" or "high intensity", as it had an additional high voltage supply for the post-deflection accelerator.

The schematic here:

http://bama.edebris.com/manuals/dumont/304

shows the differences between the 304 and the 304H. The additional circuitry used in the 304H is shown in a dotted line area in the power supply. The note near the CRT intensifier connection describes the difference in the circuit.